Over the last week, the travel media has been filledwithheadlines about Finnair wanting to weigh all of its customers before letting them on planes. Despite what you may have read in the news, you don’t have to step on a scale before boarding a Finnair flight. “We’re not weighing all passengers and will not be weighing in the future either,” Finnair spokesperson Manti Väätäinen-Pereira wrote in an email.

So what’s going on? The airline had asked for volunteers to take part in a study to help make the airline safer. Weighing customers with their carry-on baggage can help Finnair determine whether it has accurate data on passenger standard weights, which can help it figure out the overall cargo load. As with most airlines, Finnair currently uses the EASA standard weights that were collected back in 2009 (194 lb for men, 154 lb for women, 77 lb for children, all with carry-on luggage). Finnair decided to collect its own data from its own flights, because people traveling to Finland tend to have either a lot of clothing (winter requires many layers there) or very little (summer in Helsinki requires sunblock).

Finnair simply wanted its own data to improve flight performance and loading, which can translate to safer flights. Since the weight of an aircraft directly affects gas mileage, and no one wants a plane running out of gas, accurate weight information is pretty important. The most recent weigh-in is meant to update data Finnair collected in the 1980s.

Finnair asked for 150 volunteers to step on the scale in a private corner of the airport, for science. “The initial part of the study was conducted on Tuesday and Wednesday [last] week,” said Väätäinen-Pereira. “Around 180 passengers volunteered to anonymous weighing with their carry-on luggage. The feedback has been positive and customers have understood the importance of the data collection.”

Based on this initial sample, Finnair will extrapolate information on how many more customers need to be weighed to get statistically accurate data. The airline estimates it will need about 2,000 volunteers total–from travelers in winter and spring–to get an accurate dataset.